I haven't found an article saying whether the M270 is an interference or non interference engine yet. That will tell us.Also good question about the timing belt. Does it need to be replaced at a certain mileage, or do you just wait for failure?
The engine has two overhead chain-driven camshafts . Both camshaft timing is adjusted .  This, in conjunction with the turbocharger, the so-called scavenging , wherein the overlap between the opening times of inlet and outlet part. Here flushes the cold fresh air sucked in the still hot flue gas in the combustion chamber located in the exhaust manifold, which improves substantially the cylinder filling. The turbocharger speaks of the increased gas flow in the exhaust system, especially at low speeds much faster. Thus, a is turbo lag avoided. By direct the fresh air is not mixed in the fuel flowing into the cylinder, thereby scavenging losses (unburned gasoline leaking in the manifold) are avoided.